接受体外循环治疗患者分离株耐甲氧西林金黄色葡萄球菌耐药基因研究

A study of the genes responsible for the drug resistance of MRSA isolated from patients undergoing cardiopulmonary bypass

目的探讨接受体外循环治疗患者分离株耐甲氧西林金黄色葡萄球菌(MRSA)耐药情况,并对其耐药基因及流行特点进行研究,为医院MRSA感染的防治和临床用药提供指导。方法选取分离自接受体外循环治疗患者的217株金黄色葡萄球菌进行药敏试验,采用K-B头孢西丁纸片法对MRSA筛选。对217株金黄色葡萄球菌的特异基因16srRNA,femA和MRSA特有基因及万古霉素耐药基因VanA、VanB和VanC进行检测。结果 217株金黄色葡萄球菌中有75株为MRSA,占34.6%,其中2013年分离株MRSA占比最高,为42.6%,2011年为34.2%,2012年为27.6%。217株金黄色葡萄球菌中未发现万古霉素耐药株,莫西沙星耐药率为30.88%,亚胺培南耐药为37.33%。16s rRNA和femA特异基因检测217株全部阳性,MRSA特有基因mecA检测75株阳性,未检测到万古霉素耐药基因。讨论本组金黄色葡萄球菌MRSA检出率低于全国平均水平,这主要归功于医院内部进行了干预,如对医护人员进行手部等卫生管理,对医疗器械消毒等。本组MRSA中未检出万古霉素耐药株,因此万古霉素仍可作为治疗MRSA感染的一线药物。

Objectives To examine the drug resistance of methicillin-resistant Staphylococcus aureus（MRSA）and to study the genes responsible for that resistance and the epidemiological characteristics of MRSA infection for better infection control and clinical treatment.S.aureus was isolated from patients undergoing cardiopulmonary bypass at the Central Hospital of the City of Nanyang from 2011 to 2013. Methods Drug sensitivity testing was performed with 217 isolates of S.aureus,and MRSA was screened using the K-B cefoxitin disc diffusion method.The genes 16 srRNA and femA of S.aureus and mecA,VanA,VanB,and VanC of MSRA were detected using electrophoresis. Results Of the217 strains of S.aureus,75 were MSRA,accounting for 34.6% of the strains.This figure was lower than the national average.In 2013,42.6% of S.aureus strains were MRSA,and this figure was higher than that in 2011 and 2012.Testing revealed no vancomycin-resistant strains. Conclusion MSRA was detected at a lower rate than the national average because of better hygiene management（e.g.the hands of medical personnel）and disinfection of medical equipment.Testing found no vancomycin-resistant strains,so vancomycin can be used as a first-line drug for clinical treatment of MRSA.